Book returns are used by libraries and other institutions which lend books and other materials which are required to be returned within a set period of time. Book returns are useful where it is desirable to allow the borrower of materials to return them when the library or institution is closed. Book returns also make the return of materials more convenient by allowing books and materials to be returned without entering the building in which the library or institution is located. For even greater convenience, book returns may be located adjacent to a driveway or street facilitating the return of materials by a driver or passenger of a vehicle without leaving their vehicle.
An effective book return should achieve two integrated and related functions. First, it should receive the book or returned item by means of a door and pass it through to a storage container or area in such a way that it cannot be retrieved by the depositor or any unauthorized person. Known book returns employ sector-shaped doors which are pivotally mounted within a casement and are rotatively movable from an open to a closed position so that a book may be inserted into the open door, then dropped into the storage area when the door is closed. Some returns have a pivotally-mounted gate covering the rear discharge opening such that the gate can be held closed by a guide surface within the casement when the pivotally movable door is opened for deposit, thereby preventing access to the book storage area when the book deposit door is open. Although access to the interior is prevented, books may continue to be placed within the deposit door after the storage capacity of the container has been exhausted. Books placed within the door, but blocked from admittance to the container by the books within, remain accessible to weather damage or pilferage.
A book return should also prevent damage to the books when they drop into the storage container or area after passing through the depository door. If the books fall more than a foot or so the force of impact may damage them. One mechanism for maintaining a short drop distance is a self-lowering container tray, suspended by metal springs from the container rim. In this way this mechanism gives the storage container a relatively shallow depth when books first are loaded therein, but as more books are loaded the weight of the books forces the tray down, thereby providing more room for subsequently loaded books.
Frequently books, or the return cards associated with them, drop down between the movable container tray and the side walls of the container. Exposed springs which are used to support the container tray may trap the corners of books and cards. To retrieve books and cards trapped beneath the shelf, librarians must reach through a side hole, a process which is cumbersome and which may result in fingers pinched in the springs. Furthermore, container volume which would otherwise be available for storing books is occupied by the springs which extend beneath the tray.
In order to most efficiently utilize the space available in the book storage container, it is desirable that the mechanism for lowering the bottom of the container be as space efficient as possible.
A book deposit is needed which is inaccessible to further deposits when the book container is full and which effectively utilizes the book container capacity while precluding the trapping of books or cards in the container.